The past decade has witnessed unprecedented progress in our understanding of the genetic changes underlying human pancreatic cancer. Led by a long series of important contributions by Program investigators, the genetic and epigenetic basis for pancreatic cancer has slowly been unraveled, with over 30 genetic loci now recognized to undergo mutation in this disease, and characteristic changes in gene expression reported for an even larger number of coding genes and non-coding microRNAs. However, the functional contribution of these mutations to the pancreatic cancer phenotype remains largely uninvestigated. The central Aim of this Program Project Grant is to narrow the gap between genetic and functional data, by determining the functional significance of molecular alterations identified in human pancreatic cancer. This functional annotation will be pursued by examining the impact of candidate dominant and recessive mutations, as well as characteristic changes in microRNA expression, using novel cell-, zebrafish- and mouse-based assays developed by members of our group. Four projects will be pursued: Project 1: Functional annotation of human pancreatic cancer genes in a zebrafish system (Leach);Project 2: Discovery and evaluation of prioritized mutations in human pancreatic cancer (Kern);Project 3: The Hippo signaling pathway in pancreatic cancer (Maitra);and Project 4: Functional evaluation of microRNAs in pancreatic neoplasia (Mendell). These projects will be supported by three shared Cores: Core A: Cellular and Transgenic Phenotyping Core (Huso);Core B: Zebrafish Core (Parsons), and Core C: Administrative Core (Leach). The investigators pursuing these projects are all leaders in the field of pancreatic cancer research, and have an outstanding track record of synergistic interaction. The Program also leverages many already existing resources available at Johns Hopkins, including aspects of the NCI Gl SPORE grant, core resources provided by the Johns Hopkins Comprehensive Cancer Center, and the independently funded Pancreatic Cancer Genome Project. Together, these studies will dramatically accelerate the functional annotation of the pancreatic cancer genome, setting the stage for future therapeutic applications.